Charles maxwell small



'May 19, 1925. 1.538,666

f c. M. SMALL ELECTRIC SWITCH Filed July 8, 1924 Patented May 19, 19x25.

UNI-TED STATES 'CHARLES MAXWELL SMALL, QF NEW YORK, N,

ELECTRIC SWITCH.

Application led July 8, 1924. Serial No. 724,798.

ToaZZ whom 'it may kconcern.:

Be it known that I, yCHARLES M.r SMALL, of New York, "in the county of New York and State lof New York, a citizen of the United States, have inventedcertainnew and useful In'iprovements in Electric Switches, of which the following is aspecificati'on.

This invention relates r'to a switch, designed for use with a telephone, radio, or yot ier 'delicate instrument susceptible to injury by the overcharging of its circuit, but primarily for use in radio.

In installing an instrument of this nature, it is customary lto utilize 4a kcold water pipe or radiator ywithin the house as anrinstrument ground foroperatingpui'poses,fand a pipe or its equivalent buried in, the earth outdoors, andV connected `with a 'lightning switch whereby lto carry off directly to ground any electrical ycharges 'that may accumulate when lthe instrument is not inoperation.'

One of the objectsof my invention is to provide ya single article which will take ythe place of the yusual vlightning switch and ground connection therefor, as well as the instrument ground connection.

Another objectof thisinvention is to provide a Imeans of protecting the instrument from any `rovercharging of the circuit ythat might occur Jduring operation. y

My invention further contemplates a device .which may be .operated with ,facility i and reliability,.andavliich will comply with all )the requirements vof. .the rinsurance underwriters, and will beextremely simple and compact in construction, inexpensive to manufacture, andfcapable of beinginstalled withoutgreater difficult ythan attends the simple operationof boring a hole through the window frame, 1passing certain Aparts therethrough, and securing the base of the switch .in position by screws. v v

In the accompanying drawings forming part of the application, in which similar reference numerals designate like parts throughout the several views Figure lis a ,plan view of the switch showing the wiring arrangement and instru` yment connections. l

Figure 2 is an elevation taken alonvV the `line QMQ of Figure 1,.showing in detail the :wiring arrangement and connections from kthe antenna to ground.

Figure 3 is a `plan view of a modified form of switch wherein one knife bladeis omitted, and v Figure L is .a detail view in cross section of the plug which connects the switch with the instrument.

Referring more particularly to the drawings, 1 designates a base of'porcelain or other suitable insulating material, said base being preferablyy of rectangular configura tion and having suitable screw holes in convenient places for receiving 4screws or bolts by which it is attached to a suitable support.

Mounted upon the base .is a knife switch 2, suitably proportioned for use asa lightningswitch, in accordance .with insurance underwriters" requirements, and fastened to the base by means of a screw 3 countersunk therein, said switch being adapted to engage the pair of double spring contacts 4f, said contacts being likewise secured to the base by means of a countersunk screw 5. A fuse block 6 is secured .to thebase ysubstantially parallel to the aforementioned switch .by means of spring clips 7 and l7. The clip 7 is connected by suitable wiring with the screw 5 and the clip 7 is connected to a resilient leaf contact 9, the purposes of which will hereinafter appear.

A second knife switch 10 is mounted upon the base at-theoppositeend thereof from the lfirst mentioned switch 2, `the two switches being in alignment. This switchy `10 is adapted tonorinally engage a pair of spring contacts 11, said switch and contacts being fastened to the base by countersunk screws 12and 13,`respectively. The screw 12 is connected by'suitable wiring to a socket 8, hereinafter described.

A vmetallic screw socket 8 is mounted'intermediate the ends ofthe block, said socket beingadapted to receive a threaded plug 14.

' This plug contains a central contact k15 adapted to press upon the springcontact 9, aforementioned, whichfcontact 15. is connected through the plug to a wire 16. A

secondy wire 17 entering the plug is con-y nected tothe metallic shell 18 formed around the exterior of the plug, which shell engages the socket'S, as can readily be seen. wires 16 and 17 extend away from the base andconnect with the antenna and ground binding posts, respectively, of a receiving set R.

The

In using the device, it will bc seen that the normal path of the current is vfrom the antenna to the screw 3 through the switch 2, fuse 6, contact 9 to the plug 14 which has been screwed into its socket, thence to the antenna binding post of the instrument, through the instrument to ground by way ot' the plug 8 and switch 10. As the switch l0 connects to ground connection outside of the building, all inside grounds are avoided.

lllhen the instrument is not in operation the switch lO is raised and the switch 2 withdrawn from its clip Il and swung into contact with clip ll, thus a'lliording a'dircct path for current from the antenna to ground, cutting out the instrument. It is obvious that the switch 2 cannot be swung over until the switch 10 has been opened. Thus it will be seen that a single ground serves the double purpose of an instrument ground and lightning ground, and at the same time there is no possibility oi any current damaging the instrument should the ground connections beyond the switch l0 break or become defective, as the instrument is entirely out of the circuit, when not in operation.

Referring to Figure 3, a modified form of the device is disclosed, wherein the switch 10 has been removed and the socket` 8 is permanently connected direct to the clip ll. This form may be used in localities where it is preferable to use a cold water pipe inside oi' the building as an instrument ground.

The purpose ot the fuse 6 is to prevent injury to the instrument by any overcharging of the circuit during operation, said fuse being designed to protect the instrument in the usual well known manner. lli/*hen not in operation, all current-s are shunted around the instrument by throwing the switch 2 and consequently no damage can be done.

Having thus 'fully described my invention, what I claim as new and desire to secure by Letters Patent ot the United States is l. In a combined lightning arrester and switch, the combination with the antenna of a radio receiving set and a receiver, ot a member electrically connected to ground, and a switch tor making the sole electrical connection between the antenna and said member when the receiver is inoperative, a second switch independent of said lirst mentioned switch for makingan electrical connection between the receiver and said member when the receiver is operative.

2. In a combined switch and lightning arrester, thecombination with the antenna ot a radio receiving set and a receiver, of a member electrically connected to ground, a switch adapted to electrically connect the antenna and the receiver, a second switch adapted when closed to electrically connect said member and the receiver, said first mentioned switch being 'further adapted to electrically connect the antenna with said member when said last mentioned switch is open.

3. In a combined lightning arrester and switch, the combination with the antenna of a radio receiving set and a receiver of a member electrically connected to the ground, and a lever for making and breaking electrical connection between the antenna and the receiver and between the antenna and said member, a second lever for operatively connecting said member with the receiver, said first mentioned lever adapted to make connection with said member when said second lever is in inoperative position.

4l. In a combined lightning arrester and switch, the combination with the antenna of a radio receiving set and a receiver of a member electrically connected to the ground, and a lever for making and breaking electrical connection between the antenna and the receiver and between the antenna and said member, a second lever for operatively connecting said member with the receiver, said first mentioned lever adapted to make connection with said member when said second lever is in inoperative position and a fuse mounted in series with the first men` tioned lever.

5. A circuit controller to which a plurality ot elect-ric; circuits may be electrically attached, comprising a base, a plurality of switches, a ground terminal common to said switches, an antenna terminal connected to one switch and a radio receiver terminal connected to the other switch, means whereby both of said switches complete the circuit from the antenna terminal to the ground terminal, and means whereby one only of said switches completes the circuit from the antenna terminal to the ground terminal.

(i. A combined switch and lightning arrester having a 'fusible electrical connection between an antenna and a receiver' and an electrical connection between said receiver and the ground; means for breaking said last mentioned connection and other means independent thereof for directly connecting said antenna to the ground.

7. A combined lightning arrester and switch adapted to form an electrical connection between an antenna and a receiver, and between said recei ver andthe ground; means for breaking said last mentioned connection and other maans independent of said means for breaking said first mentioned connection and directly connecting said antenna to the ground.

8. A combined switch and lightning arrester adapted to form an electrical connection between an antenna and a receiver and between said receiver and the ground; means 'for breaking said last mentioned connection and other means independent thereof for breaking -said first mentioned connection and directly connecting Asaid antenna to the llt) ground, said first mentioned connection being formed in part of fusible material.

9. An article of manufacture, comprising a non-conducting base, switch levers f' mounted thereon, a threaded socket mounted in the base. a fuse mounted on the base connected between the socket and one lever, a

ground terminal, means includilngr the other of said levers for connecting said socket to said terminal.

In testimony whereof I hereunto allix my signature.

CHARLES MAXWELL SMALL. 

